Diodes Incorporated BZX84C33S-7

Overview

BZX84C33S-7 from Diodes Incorporated is a 33 V, 200 mW surface-mount Zener diode in SOT-363 package, specified with ±3% tolerance (31.0–35.0 V at 2 mA), 325 Ω maximum Zener impedance at 2 mA, and <0.1 µA reverse leakage at 23.1 V, used for precision voltage reference and overvoltage protection in low-power analog circuits.

For engineers reviewing the BZX84C33S-7 datasheet, BZX84C33S-7 pinout, BZX84C33S-7 application, or BZX84C33S-7 equivalent, key selection criteria include nominal Zener voltage accuracy, dynamic impedance at test current, thermal derating behavior, reverse leakage at rated VR, and SOT-363 footprint compatibility with high-density PCB layouts.

Technical Context

This dual-diode SOT-363 device contains two independent Zener junctions sharing no internal connection - each functions as a discrete 33 V voltage clamp. It operates under DC or low-frequency transient conditions with thermal resistance of 625 °C/W on FR4 board, enabling stable regulation up to +125 °C ambient when power dissipation remains within derated limits.

Zener breakdown is achieved via controlled avalanche mechanism at 2 mA test current, with temperature coefficient ranging from +27.4 mV/°C to +33.4 mV/°C - indicating positive drift above 25 °C, requiring compensation in precision references. Capacitance is not characterized per diode but typical total capacitance for 33 V devices is ~15 pF at 1 MHz and 1 V reverse bias.

Key Specifications

Pinout & Package

SOT-363 package houses two isolated Zener diodes in one compact plastic body. Pin numbering follows standard top-view orientation: Pin 1 (NC), Pin 2 (Cathode 1), Pin 3 (Anode 1), Pin 4 (Anode 2), Pin 5 (Cathode 2), Pin 6 (NC). No internal connection between diodes; NC pins are unconnected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage reference applications.

Compared with MMBZ5262BS-7-F and BZX84C33LT1G, BZX84C33S-7 uniquely delivers dual 33 V Zeners in minimal area with optimized 2 mA test condition for low-power biasing, making it preferred for space-constrained dual-reference or fault-tolerant designs.

Availability

BZX84C33S-7 is available at Aetrix Electronics and suitable for industrial sensor conditioning, USB-C power delivery protection, low-power IoT voltage reference, and automotive body control module reset circuits requiring stable component supply and full traceability.

Supply support for BZX84C33S-7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, serving industrial, computing, consumer, and communications markets with high-reliability components.

BZX84C33S-7 belongs to the BZX84C series of dual Zener diodes designed specifically for space-constrained voltage regulation and transient suppression in portable and automotive electronics where dual-channel protection or reference is required.

FAQ

What is the maximum continuous reverse voltage this device can withstand without breakdown?

The BZX84C33S-7 has a nominal Zener voltage of 33 V with guaranteed breakdown between 31.0 V and 35.0 V at 2 mA. Its absolute maximum non-breakdown reverse voltage is 23.1 V - exceeding this value risks entering the Zener region, and sustained operation above 35.0 V may cause thermal runaway if power dissipation exceeds 200 mW.

Can both Zener diodes be used simultaneously with shared cathodes?

No. Pins 2 and 5 are independent cathodes; Pins 3 and 4 are independent anodes; there is no internal connection between them. Shared cathode use would require external wiring and introduces parasitic inductance/capacitance that degrades transient response - the device is intended for fully isolated dual-channel operation only.

Is this part suitable for use in a 125 °C under-hood automotive environment?

Yes. The BZX84C33S-7 is rated for junction temperatures from −65 °C to +150 °C. At 125 °C ambient, its power dissipation must be derated to approximately 100 mW (per Fig. 1 derating curve), which supports reliable operation at ≤0.5 mA average Zener current - sufficient for reference biasing in most automotive microcontroller reset circuits.

Does the SOT-363 package support reflow soldering per IPC-J-STD-020?

Yes. The device meets Moisture Sensitivity Level 1 per J-STD-020D and is qualified for standard Pb-free reflow profiles (peak 260 °C, 30 sec max). Its matte tin plating and UL 94V-0 mold compound ensure robust solder joint formation and thermal stability during assembly without preconditioning.